Detection of Down syndrome during pregnancy improves for younger women

New figures from the National Down Syndrome Cytogenetic Register (NDSCR) based at Queen Mary University of London, reveal the proportion of Down syndrome cases diagnosed antenatally has increased in younger women. Furthermore, Down syndrome diagnoses are occurring earlier in pregnancy for women of all ages.

The NDSCR is the only national source of data on pre and postnatal diagnoses of Down, Patau and Edwards syndrome cases in England and Wales. The latest figures are captured in the new NDSCR Annual Report 2012.

Key findings from the report (all figures from 2012):

There were 1,982 diagnoses of Down syndrome, 64% of which were made during pregnancy.

There were an estimated 775 babies born with Down syndrome (an increase from 739 in 2011 and 734 in 2010).

The proportion of women under 35 receiving a diagnosis of Down syndrome during pregnancy has increased from 54% in 2008 to 66% in 2012. The proportion for women 35 and over remained constant at 71% from 2008 to 2012.

The proportion of women receiving a diagnoses of Down syndrome during pregnancy after screening in the first three months of pregnancy (first trimester) increased from 45% in 2008 to 77% in 2012 for women under 35 and from 68% in 2008 to 80% of 2012 for women 35 and over.

The proportion of women having a termination after a diagnosis of Down syndrome during pregnancy has decreased from 92% in 1989-2010 to 90% in 2011-12.

The data also shows there were regional differences in the type of screening women were offered. In all the English regions the majority of women were diagnosed after first trimester screening (81%), compared to less than a third of women (31%) in Wales. These differences may arise not only due to service factors, but also maternal factors including age, social deprivation and cultural beliefs influencing the take up of screening and diagnostic tests.

Joan Morris, Professor of Medical Statistics at Queen Mary University of London, Barts and The London School of Medicine and Dentistry, comments: “It is positive to see that antenatal screening for Down syndrome is improving, particularly for women under 35. We are now seeing Down syndrome being detected at an earlier stage of pregnancy for all women, usually within the first three months.”

“It is very important that women are given the facts around Down syndrome and pregnancy as early as possible so they can make the right decision for their personal circumstances. We are now seeing more women choosing to continue with the pregnancy after receiving a diagnosis of Down syndrome.”